<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no">
    <title>Title</title>
    <script src="../jquery/jquery-3.2.1.min.js"></script>
    <script src="../js/bootstrap.min.js"></script>
    <link rel="stylesheet" href="../css/bootstrap.css">
</head>
<style>
    .container{
        width: 450px;
        height: 300px;
        position: absolute;
        left:50%;
        top:50%;
        transform: translate(-50%,-50%);
        background-color: white;
        border-radius: 10px;
    }
</style>
<body style="background-color: #0f0f0f">

    <div class="container">

        <form role="form">
            <h3 class="text-center">后台登录界面</h3>

            <div class="form-group">

                <label for="name">用户名</label>
                <input type="text" id="name" placeholder="请输入用户名" class="form-control">

            </div>
            <div class="form-group">

                <label for="pass">密码</label>
                <input type="text" id="pass" placeholder="请输入用密码" class="form-control">

            </div>
            <div class="checkbox">
               <label><input type="checkbox">请记住我</label>
            </div>
            <button type="submit" class="btn btn-block btn-success">登录</button>
        </form>

    </div>
</body>
</html>